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[linux-2.6/btrfs-unstable.git] / lib / debugobjects.c
blob994be4805ceca93dd417baf2289eff8f5446c4f5
1 /*
2 * Generic infrastructure for lifetime debugging of objects.
3 *
4 * Started by Thomas Gleixner
5 *
6 * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
7 *
8 * For licencing details see kernel-base/COPYING
9 */
10
11 #define pr_fmt(fmt) "ODEBUG: " fmt
12
13 #include <linux/debugobjects.h>
14 #include <linux/interrupt.h>
15 #include <linux/sched.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/seq_file.h>
18 #include <linux/debugfs.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/kmemleak.h>
22
23 #define ODEBUG_HASH_BITS 14
24 #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
25
26 #define ODEBUG_POOL_SIZE 1024
27 #define ODEBUG_POOL_MIN_LEVEL 256
28
29 #define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
30 #define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
31 #define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
32
33 struct debug_bucket {
34 struct hlist_head list;
35 raw_spinlock_t lock;
36 };
37
38 static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
39
40 static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
41
42 static DEFINE_RAW_SPINLOCK(pool_lock);
43
44 static HLIST_HEAD(obj_pool);
45 static HLIST_HEAD(obj_to_free);
46
47 static int obj_pool_min_free = ODEBUG_POOL_SIZE;
48 static int obj_pool_free = ODEBUG_POOL_SIZE;
49 static int obj_pool_used;
50 static int obj_pool_max_used;
51 /* The number of objs on the global free list */
52 static int obj_nr_tofree;
53 static struct kmem_cache *obj_cache;
54
55 static int debug_objects_maxchain __read_mostly;
56 static int __maybe_unused debug_objects_maxchecked __read_mostly;
57 static int debug_objects_fixups __read_mostly;
58 static int debug_objects_warnings __read_mostly;
59 static int debug_objects_enabled __read_mostly
60 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
61 static int debug_objects_pool_size __read_mostly
62 = ODEBUG_POOL_SIZE;
63 static int debug_objects_pool_min_level __read_mostly
64 = ODEBUG_POOL_MIN_LEVEL;
65 static struct debug_obj_descr *descr_test __read_mostly;
66
67 /*
68 * Track numbers of kmem_cache_alloc()/free() calls done.
69 */
70 static int debug_objects_allocated;
71 static int debug_objects_freed;
72
73 static void free_obj_work(struct work_struct *work);
74 static DECLARE_WORK(debug_obj_work, free_obj_work);
75
76 static int __init enable_object_debug(char *str)
77 {
78 debug_objects_enabled = 1;
79 return 0;
80 }
81
82 static int __init disable_object_debug(char *str)
83 {
84 debug_objects_enabled = 0;
85 return 0;
86 }
87
88 early_param("debug_objects", enable_object_debug);
89 early_param("no_debug_objects", disable_object_debug);
90
91 static const char *obj_states[ODEBUG_STATE_MAX] = {
92 [ODEBUG_STATE_NONE] = "none",
93 [ODEBUG_STATE_INIT] = "initialized",
94 [ODEBUG_STATE_INACTIVE] = "inactive",
95 [ODEBUG_STATE_ACTIVE] = "active",
96 [ODEBUG_STATE_DESTROYED] = "destroyed",
97 [ODEBUG_STATE_NOTAVAILABLE] = "not available",
98 };
99
100 static void fill_pool(void)
101 {
102 gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
103 struct debug_obj *new, *obj;
104 unsigned long flags;
105
106 if (likely(obj_pool_free >= debug_objects_pool_min_level))
107 return;
108
109 /*
110 * Reuse objs from the global free list; they will be reinitialized
111 * when allocating.
112 */
113 while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
114 raw_spin_lock_irqsave(&pool_lock, flags);
115 /*
116 * Recheck with the lock held as the worker thread might have
117 * won the race and freed the global free list already.
118 */
119 if (obj_nr_tofree) {
120 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
121 hlist_del(&obj->node);
122 obj_nr_tofree--;
123 hlist_add_head(&obj->node, &obj_pool);
124 obj_pool_free++;
125 }
126 raw_spin_unlock_irqrestore(&pool_lock, flags);
127 }
128
129 if (unlikely(!obj_cache))
130 return;
131
132 while (obj_pool_free < debug_objects_pool_min_level) {
133
134 new = kmem_cache_zalloc(obj_cache, gfp);
135 if (!new)
136 return;
137
138 kmemleak_ignore(new);
139 raw_spin_lock_irqsave(&pool_lock, flags);
140 hlist_add_head(&new->node, &obj_pool);
141 debug_objects_allocated++;
142 obj_pool_free++;
143 raw_spin_unlock_irqrestore(&pool_lock, flags);
144 }
145 }
146
147 /*
148 * Lookup an object in the hash bucket.
149 */
150 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
151 {
152 struct debug_obj *obj;
153 int cnt = 0;
154
155 hlist_for_each_entry(obj, &b->list, node) {
156 cnt++;
157 if (obj->object == addr)
158 return obj;
159 }
160 if (cnt > debug_objects_maxchain)
161 debug_objects_maxchain = cnt;
162
163 return NULL;
164 }
165
166 /*
167 * Allocate a new object. If the pool is empty, switch off the debugger.
168 * Must be called with interrupts disabled.
169 */
170 static struct debug_obj *
171 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
172 {
173 struct debug_obj *obj = NULL;
174
175 raw_spin_lock(&pool_lock);
176 if (obj_pool.first) {
177 obj = hlist_entry(obj_pool.first, typeof(*obj), node);
178
179 obj->object = addr;
180 obj->descr = descr;
181 obj->state = ODEBUG_STATE_NONE;
182 obj->astate = 0;
183 hlist_del(&obj->node);
184
185 hlist_add_head(&obj->node, &b->list);
186
187 obj_pool_used++;
188 if (obj_pool_used > obj_pool_max_used)
189 obj_pool_max_used = obj_pool_used;
190
191 obj_pool_free--;
192 if (obj_pool_free < obj_pool_min_free)
193 obj_pool_min_free = obj_pool_free;
194 }
195 raw_spin_unlock(&pool_lock);
196
197 return obj;
198 }
199
200 /*
201 * workqueue function to free objects.
202 *
203 * To reduce contention on the global pool_lock, the actual freeing of
204 * debug objects will be delayed if the pool_lock is busy.
205 */
206 static void free_obj_work(struct work_struct *work)
207 {
208 struct hlist_node *tmp;
209 struct debug_obj *obj;
210 unsigned long flags;
211 HLIST_HEAD(tofree);
212
213 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
214 return;
215
216 /*
217 * The objs on the pool list might be allocated before the work is
218 * run, so recheck if pool list it full or not, if not fill pool
219 * list from the global free list
220 */
221 while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) {
222 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
223 hlist_del(&obj->node);
224 hlist_add_head(&obj->node, &obj_pool);
225 obj_pool_free++;
226 obj_nr_tofree--;
227 }
228
229 /*
230 * Pool list is already full and there are still objs on the free
231 * list. Move remaining free objs to a temporary list to free the
232 * memory outside the pool_lock held region.
233 */
234 if (obj_nr_tofree) {
235 hlist_move_list(&obj_to_free, &tofree);
236 debug_objects_freed += obj_nr_tofree;
237 obj_nr_tofree = 0;
238 }
239 raw_spin_unlock_irqrestore(&pool_lock, flags);
240
241 hlist_for_each_entry_safe(obj, tmp, &tofree, node) {
242 hlist_del(&obj->node);
243 kmem_cache_free(obj_cache, obj);
244 }
245 }
246
247 static bool __free_object(struct debug_obj *obj)
248 {
249 unsigned long flags;
250 bool work;
251
252 raw_spin_lock_irqsave(&pool_lock, flags);
253 work = (obj_pool_free > debug_objects_pool_size) && obj_cache;
254 obj_pool_used--;
255
256 if (work) {
257 obj_nr_tofree++;
258 hlist_add_head(&obj->node, &obj_to_free);
259 } else {
260 obj_pool_free++;
261 hlist_add_head(&obj->node, &obj_pool);
262 }
263 raw_spin_unlock_irqrestore(&pool_lock, flags);
264 return work;
265 }
266
267 /*
268 * Put the object back into the pool and schedule work to free objects
269 * if necessary.
270 */
271 static void free_object(struct debug_obj *obj)
272 {
273 if (__free_object(obj))
274 schedule_work(&debug_obj_work);
275 }
276
277 /*
278 * We run out of memory. That means we probably have tons of objects
279 * allocated.
280 */
281 static void debug_objects_oom(void)
282 {
283 struct debug_bucket *db = obj_hash;
284 struct hlist_node *tmp;
285 HLIST_HEAD(freelist);
286 struct debug_obj *obj;
287 unsigned long flags;
288 int i;
289
290 pr_warn("Out of memory. ODEBUG disabled\n");
291
292 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
293 raw_spin_lock_irqsave(&db->lock, flags);
294 hlist_move_list(&db->list, &freelist);
295 raw_spin_unlock_irqrestore(&db->lock, flags);
296
297 /* Now free them */
298 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
299 hlist_del(&obj->node);
300 free_object(obj);
301 }
302 }
303 }
304
305 /*
306 * We use the pfn of the address for the hash. That way we can check
307 * for freed objects simply by checking the affected bucket.
308 */
309 static struct debug_bucket *get_bucket(unsigned long addr)
310 {
311 unsigned long hash;
312
313 hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
314 return &obj_hash[hash];
315 }
316
317 static void debug_print_object(struct debug_obj *obj, char *msg)
318 {
319 struct debug_obj_descr *descr = obj->descr;
320 static int limit;
321
322 if (limit < 5 && descr != descr_test) {
323 void *hint = descr->debug_hint ?
324 descr->debug_hint(obj->object) : NULL;
325 limit++;
326 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
327 "object type: %s hint: %pS\n",
328 msg, obj_states[obj->state], obj->astate,
329 descr->name, hint);
330 }
331 debug_objects_warnings++;
332 }
333
334 /*
335 * Try to repair the damage, so we have a better chance to get useful
336 * debug output.
337 */
338 static bool
339 debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
340 void * addr, enum debug_obj_state state)
341 {
342 if (fixup && fixup(addr, state)) {
343 debug_objects_fixups++;
344 return true;
345 }
346 return false;
347 }
348
349 static void debug_object_is_on_stack(void *addr, int onstack)
350 {
351 int is_on_stack;
352 static int limit;
353
354 if (limit > 4)
355 return;
356
357 is_on_stack = object_is_on_stack(addr);
358 if (is_on_stack == onstack)
359 return;
360
361 limit++;
362 if (is_on_stack)
363 pr_warn("object is on stack, but not annotated\n");
364 else
365 pr_warn("object is not on stack, but annotated\n");
366 WARN_ON(1);
367 }
368
369 static void
370 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
371 {
372 enum debug_obj_state state;
373 struct debug_bucket *db;
374 struct debug_obj *obj;
375 unsigned long flags;
376
377 fill_pool();
378
379 db = get_bucket((unsigned long) addr);
380
381 raw_spin_lock_irqsave(&db->lock, flags);
382
383 obj = lookup_object(addr, db);
384 if (!obj) {
385 obj = alloc_object(addr, db, descr);
386 if (!obj) {
387 debug_objects_enabled = 0;
388 raw_spin_unlock_irqrestore(&db->lock, flags);
389 debug_objects_oom();
390 return;
391 }
392 debug_object_is_on_stack(addr, onstack);
393 }
394
395 switch (obj->state) {
396 case ODEBUG_STATE_NONE:
397 case ODEBUG_STATE_INIT:
398 case ODEBUG_STATE_INACTIVE:
399 obj->state = ODEBUG_STATE_INIT;
400 break;
401
402 case ODEBUG_STATE_ACTIVE:
403 debug_print_object(obj, "init");
404 state = obj->state;
405 raw_spin_unlock_irqrestore(&db->lock, flags);
406 debug_object_fixup(descr->fixup_init, addr, state);
407 return;
408
409 case ODEBUG_STATE_DESTROYED:
410 debug_print_object(obj, "init");
411 break;
412 default:
413 break;
414 }
415
416 raw_spin_unlock_irqrestore(&db->lock, flags);
417 }
418
419 /**
420 * debug_object_init - debug checks when an object is initialized
421 * @addr: address of the object
422 * @descr: pointer to an object specific debug description structure
423 */
424 void debug_object_init(void *addr, struct debug_obj_descr *descr)
425 {
426 if (!debug_objects_enabled)
427 return;
428
429 __debug_object_init(addr, descr, 0);
430 }
431 EXPORT_SYMBOL_GPL(debug_object_init);
432
433 /**
434 * debug_object_init_on_stack - debug checks when an object on stack is
435 * initialized
436 * @addr: address of the object
437 * @descr: pointer to an object specific debug description structure
438 */
439 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
440 {
441 if (!debug_objects_enabled)
442 return;
443
444 __debug_object_init(addr, descr, 1);
445 }
446 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
447
448 /**
449 * debug_object_activate - debug checks when an object is activated
450 * @addr: address of the object
451 * @descr: pointer to an object specific debug description structure
452 * Returns 0 for success, -EINVAL for check failed.
453 */
454 int debug_object_activate(void *addr, struct debug_obj_descr *descr)
455 {
456 enum debug_obj_state state;
457 struct debug_bucket *db;
458 struct debug_obj *obj;
459 unsigned long flags;
460 int ret;
461 struct debug_obj o = { .object = addr,
462 .state = ODEBUG_STATE_NOTAVAILABLE,
463 .descr = descr };
464
465 if (!debug_objects_enabled)
466 return 0;
467
468 db = get_bucket((unsigned long) addr);
469
470 raw_spin_lock_irqsave(&db->lock, flags);
471
472 obj = lookup_object(addr, db);
473 if (obj) {
474 switch (obj->state) {
475 case ODEBUG_STATE_INIT:
476 case ODEBUG_STATE_INACTIVE:
477 obj->state = ODEBUG_STATE_ACTIVE;
478 ret = 0;
479 break;
480
481 case ODEBUG_STATE_ACTIVE:
482 debug_print_object(obj, "activate");
483 state = obj->state;
484 raw_spin_unlock_irqrestore(&db->lock, flags);
485 ret = debug_object_fixup(descr->fixup_activate, addr, state);
486 return ret ? 0 : -EINVAL;
487
488 case ODEBUG_STATE_DESTROYED:
489 debug_print_object(obj, "activate");
490 ret = -EINVAL;
491 break;
492 default:
493 ret = 0;
494 break;
495 }
496 raw_spin_unlock_irqrestore(&db->lock, flags);
497 return ret;
498 }
499
500 raw_spin_unlock_irqrestore(&db->lock, flags);
501 /*
502 * We are here when a static object is activated. We
503 * let the type specific code confirm whether this is
504 * true or not. if true, we just make sure that the
505 * static object is tracked in the object tracker. If
506 * not, this must be a bug, so we try to fix it up.
507 */
508 if (descr->is_static_object && descr->is_static_object(addr)) {
509 /* track this static object */
510 debug_object_init(addr, descr);
511 debug_object_activate(addr, descr);
512 } else {
513 debug_print_object(&o, "activate");
514 ret = debug_object_fixup(descr->fixup_activate, addr,
515 ODEBUG_STATE_NOTAVAILABLE);
516 return ret ? 0 : -EINVAL;
517 }
518 return 0;
519 }
520 EXPORT_SYMBOL_GPL(debug_object_activate);
521
522 /**
523 * debug_object_deactivate - debug checks when an object is deactivated
524 * @addr: address of the object
525 * @descr: pointer to an object specific debug description structure
526 */
527 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
528 {
529 struct debug_bucket *db;
530 struct debug_obj *obj;
531 unsigned long flags;
532
533 if (!debug_objects_enabled)
534 return;
535
536 db = get_bucket((unsigned long) addr);
537
538 raw_spin_lock_irqsave(&db->lock, flags);
539
540 obj = lookup_object(addr, db);
541 if (obj) {
542 switch (obj->state) {
543 case ODEBUG_STATE_INIT:
544 case ODEBUG_STATE_INACTIVE:
545 case ODEBUG_STATE_ACTIVE:
546 if (!obj->astate)
547 obj->state = ODEBUG_STATE_INACTIVE;
548 else
549 debug_print_object(obj, "deactivate");
550 break;
551
552 case ODEBUG_STATE_DESTROYED:
553 debug_print_object(obj, "deactivate");
554 break;
555 default:
556 break;
557 }
558 } else {
559 struct debug_obj o = { .object = addr,
560 .state = ODEBUG_STATE_NOTAVAILABLE,
561 .descr = descr };
562
563 debug_print_object(&o, "deactivate");
564 }
565
566 raw_spin_unlock_irqrestore(&db->lock, flags);
567 }
568 EXPORT_SYMBOL_GPL(debug_object_deactivate);
569
570 /**
571 * debug_object_destroy - debug checks when an object is destroyed
572 * @addr: address of the object
573 * @descr: pointer to an object specific debug description structure
574 */
575 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
576 {
577 enum debug_obj_state state;
578 struct debug_bucket *db;
579 struct debug_obj *obj;
580 unsigned long flags;
581
582 if (!debug_objects_enabled)
583 return;
584
585 db = get_bucket((unsigned long) addr);
586
587 raw_spin_lock_irqsave(&db->lock, flags);
588
589 obj = lookup_object(addr, db);
590 if (!obj)
591 goto out_unlock;
592
593 switch (obj->state) {
594 case ODEBUG_STATE_NONE:
595 case ODEBUG_STATE_INIT:
596 case ODEBUG_STATE_INACTIVE:
597 obj->state = ODEBUG_STATE_DESTROYED;
598 break;
599 case ODEBUG_STATE_ACTIVE:
600 debug_print_object(obj, "destroy");
601 state = obj->state;
602 raw_spin_unlock_irqrestore(&db->lock, flags);
603 debug_object_fixup(descr->fixup_destroy, addr, state);
604 return;
605
606 case ODEBUG_STATE_DESTROYED:
607 debug_print_object(obj, "destroy");
608 break;
609 default:
610 break;
611 }
612 out_unlock:
613 raw_spin_unlock_irqrestore(&db->lock, flags);
614 }
615 EXPORT_SYMBOL_GPL(debug_object_destroy);
616
617 /**
618 * debug_object_free - debug checks when an object is freed
619 * @addr: address of the object
620 * @descr: pointer to an object specific debug description structure
621 */
622 void debug_object_free(void *addr, struct debug_obj_descr *descr)
623 {
624 enum debug_obj_state state;
625 struct debug_bucket *db;
626 struct debug_obj *obj;
627 unsigned long flags;
628
629 if (!debug_objects_enabled)
630 return;
631
632 db = get_bucket((unsigned long) addr);
633
634 raw_spin_lock_irqsave(&db->lock, flags);
635
636 obj = lookup_object(addr, db);
637 if (!obj)
638 goto out_unlock;
639
640 switch (obj->state) {
641 case ODEBUG_STATE_ACTIVE:
642 debug_print_object(obj, "free");
643 state = obj->state;
644 raw_spin_unlock_irqrestore(&db->lock, flags);
645 debug_object_fixup(descr->fixup_free, addr, state);
646 return;
647 default:
648 hlist_del(&obj->node);
649 raw_spin_unlock_irqrestore(&db->lock, flags);
650 free_object(obj);
651 return;
652 }
653 out_unlock:
654 raw_spin_unlock_irqrestore(&db->lock, flags);
655 }
656 EXPORT_SYMBOL_GPL(debug_object_free);
657
658 /**
659 * debug_object_assert_init - debug checks when object should be init-ed
660 * @addr: address of the object
661 * @descr: pointer to an object specific debug description structure
662 */
663 void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
664 {
665 struct debug_bucket *db;
666 struct debug_obj *obj;
667 unsigned long flags;
668
669 if (!debug_objects_enabled)
670 return;
671
672 db = get_bucket((unsigned long) addr);
673
674 raw_spin_lock_irqsave(&db->lock, flags);
675
676 obj = lookup_object(addr, db);
677 if (!obj) {
678 struct debug_obj o = { .object = addr,
679 .state = ODEBUG_STATE_NOTAVAILABLE,
680 .descr = descr };
681
682 raw_spin_unlock_irqrestore(&db->lock, flags);
683 /*
684 * Maybe the object is static, and we let the type specific
685 * code confirm. Track this static object if true, else invoke
686 * fixup.
687 */
688 if (descr->is_static_object && descr->is_static_object(addr)) {
689 /* Track this static object */
690 debug_object_init(addr, descr);
691 } else {
692 debug_print_object(&o, "assert_init");
693 debug_object_fixup(descr->fixup_assert_init, addr,
694 ODEBUG_STATE_NOTAVAILABLE);
695 }
696 return;
697 }
698
699 raw_spin_unlock_irqrestore(&db->lock, flags);
700 }
701 EXPORT_SYMBOL_GPL(debug_object_assert_init);
702
703 /**
704 * debug_object_active_state - debug checks object usage state machine
705 * @addr: address of the object
706 * @descr: pointer to an object specific debug description structure
707 * @expect: expected state
708 * @next: state to move to if expected state is found
709 */
710 void
711 debug_object_active_state(void *addr, struct debug_obj_descr *descr,
712 unsigned int expect, unsigned int next)
713 {
714 struct debug_bucket *db;
715 struct debug_obj *obj;
716 unsigned long flags;
717
718 if (!debug_objects_enabled)
719 return;
720
721 db = get_bucket((unsigned long) addr);
722
723 raw_spin_lock_irqsave(&db->lock, flags);
724
725 obj = lookup_object(addr, db);
726 if (obj) {
727 switch (obj->state) {
728 case ODEBUG_STATE_ACTIVE:
729 if (obj->astate == expect)
730 obj->astate = next;
731 else
732 debug_print_object(obj, "active_state");
733 break;
734
735 default:
736 debug_print_object(obj, "active_state");
737 break;
738 }
739 } else {
740 struct debug_obj o = { .object = addr,
741 .state = ODEBUG_STATE_NOTAVAILABLE,
742 .descr = descr };
743
744 debug_print_object(&o, "active_state");
745 }
746
747 raw_spin_unlock_irqrestore(&db->lock, flags);
748 }
749 EXPORT_SYMBOL_GPL(debug_object_active_state);
750
751 #ifdef CONFIG_DEBUG_OBJECTS_FREE
752 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
753 {
754 unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
755 struct debug_obj_descr *descr;
756 enum debug_obj_state state;
757 struct debug_bucket *db;
758 struct hlist_node *tmp;
759 struct debug_obj *obj;
760 int cnt, objs_checked = 0;
761 bool work = false;
762
763 saddr = (unsigned long) address;
764 eaddr = saddr + size;
765 paddr = saddr & ODEBUG_CHUNK_MASK;
766 chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
767 chunks >>= ODEBUG_CHUNK_SHIFT;
768
769 for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
770 db = get_bucket(paddr);
771
772 repeat:
773 cnt = 0;
774 raw_spin_lock_irqsave(&db->lock, flags);
775 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
776 cnt++;
777 oaddr = (unsigned long) obj->object;
778 if (oaddr < saddr || oaddr >= eaddr)
779 continue;
780
781 switch (obj->state) {
782 case ODEBUG_STATE_ACTIVE:
783 debug_print_object(obj, "free");
784 descr = obj->descr;
785 state = obj->state;
786 raw_spin_unlock_irqrestore(&db->lock, flags);
787 debug_object_fixup(descr->fixup_free,
788 (void *) oaddr, state);
789 goto repeat;
790 default:
791 hlist_del(&obj->node);
792 work |= __free_object(obj);
793 break;
794 }
795 }
796 raw_spin_unlock_irqrestore(&db->lock, flags);
797
798 if (cnt > debug_objects_maxchain)
799 debug_objects_maxchain = cnt;
800
801 objs_checked += cnt;
802 }
803
804 if (objs_checked > debug_objects_maxchecked)
805 debug_objects_maxchecked = objs_checked;
806
807 /* Schedule work to actually kmem_cache_free() objects */
808 if (work)
809 schedule_work(&debug_obj_work);
810 }
811
812 void debug_check_no_obj_freed(const void *address, unsigned long size)
813 {
814 if (debug_objects_enabled)
815 __debug_check_no_obj_freed(address, size);
816 }
817 #endif
818
819 #ifdef CONFIG_DEBUG_FS
820
821 static int debug_stats_show(struct seq_file *m, void *v)
822 {
823 seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
824 seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked);
825 seq_printf(m, "warnings :%d\n", debug_objects_warnings);
826 seq_printf(m, "fixups :%d\n", debug_objects_fixups);
827 seq_printf(m, "pool_free :%d\n", obj_pool_free);
828 seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
829 seq_printf(m, "pool_used :%d\n", obj_pool_used);
830 seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
831 seq_printf(m, "on_free_list :%d\n", obj_nr_tofree);
832 seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
833 seq_printf(m, "objs_freed :%d\n", debug_objects_freed);
834 return 0;
835 }
836
837 static int debug_stats_open(struct inode *inode, struct file *filp)
838 {
839 return single_open(filp, debug_stats_show, NULL);
840 }
841
842 static const struct file_operations debug_stats_fops = {
843 .open = debug_stats_open,
844 .read = seq_read,
845 .llseek = seq_lseek,
846 .release = single_release,
847 };
848
849 static int __init debug_objects_init_debugfs(void)
850 {
851 struct dentry *dbgdir, *dbgstats;
852
853 if (!debug_objects_enabled)
854 return 0;
855
856 dbgdir = debugfs_create_dir("debug_objects", NULL);
857 if (!dbgdir)
858 return -ENOMEM;
859
860 dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
861 &debug_stats_fops);
862 if (!dbgstats)
863 goto err;
864
865 return 0;
866
867 err:
868 debugfs_remove(dbgdir);
869
870 return -ENOMEM;
871 }
872 __initcall(debug_objects_init_debugfs);
873
874 #else
875 static inline void debug_objects_init_debugfs(void) { }
876 #endif
877
878 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
879
880 /* Random data structure for the self test */
881 struct self_test {
882 unsigned long dummy1[6];
883 int static_init;
884 unsigned long dummy2[3];
885 };
886
887 static __initdata struct debug_obj_descr descr_type_test;
888
889 static bool __init is_static_object(void *addr)
890 {
891 struct self_test *obj = addr;
892
893 return obj->static_init;
894 }
895
896 /*
897 * fixup_init is called when:
898 * - an active object is initialized
899 */
900 static bool __init fixup_init(void *addr, enum debug_obj_state state)
901 {
902 struct self_test *obj = addr;
903
904 switch (state) {
905 case ODEBUG_STATE_ACTIVE:
906 debug_object_deactivate(obj, &descr_type_test);
907 debug_object_init(obj, &descr_type_test);
908 return true;
909 default:
910 return false;
911 }
912 }
913
914 /*
915 * fixup_activate is called when:
916 * - an active object is activated
917 * - an unknown non-static object is activated
918 */
919 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
920 {
921 struct self_test *obj = addr;
922
923 switch (state) {
924 case ODEBUG_STATE_NOTAVAILABLE:
925 return true;
926 case ODEBUG_STATE_ACTIVE:
927 debug_object_deactivate(obj, &descr_type_test);
928 debug_object_activate(obj, &descr_type_test);
929 return true;
930
931 default:
932 return false;
933 }
934 }
935
936 /*
937 * fixup_destroy is called when:
938 * - an active object is destroyed
939 */
940 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
941 {
942 struct self_test *obj = addr;
943
944 switch (state) {
945 case ODEBUG_STATE_ACTIVE:
946 debug_object_deactivate(obj, &descr_type_test);
947 debug_object_destroy(obj, &descr_type_test);
948 return true;
949 default:
950 return false;
951 }
952 }
953
954 /*
955 * fixup_free is called when:
956 * - an active object is freed
957 */
958 static bool __init fixup_free(void *addr, enum debug_obj_state state)
959 {
960 struct self_test *obj = addr;
961
962 switch (state) {
963 case ODEBUG_STATE_ACTIVE:
964 debug_object_deactivate(obj, &descr_type_test);
965 debug_object_free(obj, &descr_type_test);
966 return true;
967 default:
968 return false;
969 }
970 }
971
972 static int __init
973 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
974 {
975 struct debug_bucket *db;
976 struct debug_obj *obj;
977 unsigned long flags;
978 int res = -EINVAL;
979
980 db = get_bucket((unsigned long) addr);
981
982 raw_spin_lock_irqsave(&db->lock, flags);
983
984 obj = lookup_object(addr, db);
985 if (!obj && state != ODEBUG_STATE_NONE) {
986 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
987 goto out;
988 }
989 if (obj && obj->state != state) {
990 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
991 obj->state, state);
992 goto out;
993 }
994 if (fixups != debug_objects_fixups) {
995 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
996 fixups, debug_objects_fixups);
997 goto out;
998 }
999 if (warnings != debug_objects_warnings) {
1000 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
1001 warnings, debug_objects_warnings);
1002 goto out;
1003 }
1004 res = 0;
1005 out:
1006 raw_spin_unlock_irqrestore(&db->lock, flags);
1007 if (res)
1008 debug_objects_enabled = 0;
1009 return res;
1010 }
1011
1012 static __initdata struct debug_obj_descr descr_type_test = {
1013 .name = "selftest",
1014 .is_static_object = is_static_object,
1015 .fixup_init = fixup_init,
1016 .fixup_activate = fixup_activate,
1017 .fixup_destroy = fixup_destroy,
1018 .fixup_free = fixup_free,
1019 };
1020
1021 static __initdata struct self_test obj = { .static_init = 0 };
1022
1023 static void __init debug_objects_selftest(void)
1024 {
1025 int fixups, oldfixups, warnings, oldwarnings;
1026 unsigned long flags;
1027
1028 local_irq_save(flags);
1029
1030 fixups = oldfixups = debug_objects_fixups;
1031 warnings = oldwarnings = debug_objects_warnings;
1032 descr_test = &descr_type_test;
1033
1034 debug_object_init(&obj, &descr_type_test);
1035 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1036 goto out;
1037 debug_object_activate(&obj, &descr_type_test);
1038 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1039 goto out;
1040 debug_object_activate(&obj, &descr_type_test);
1041 if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
1042 goto out;
1043 debug_object_deactivate(&obj, &descr_type_test);
1044 if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1045 goto out;
1046 debug_object_destroy(&obj, &descr_type_test);
1047 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1048 goto out;
1049 debug_object_init(&obj, &descr_type_test);
1050 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1051 goto out;
1052 debug_object_activate(&obj, &descr_type_test);
1053 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1054 goto out;
1055 debug_object_deactivate(&obj, &descr_type_test);
1056 if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1057 goto out;
1058 debug_object_free(&obj, &descr_type_test);
1059 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1060 goto out;
1061
1062 obj.static_init = 1;
1063 debug_object_activate(&obj, &descr_type_test);
1064 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1065 goto out;
1066 debug_object_init(&obj, &descr_type_test);
1067 if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1068 goto out;
1069 debug_object_free(&obj, &descr_type_test);
1070 if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1071 goto out;
1072
1073 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1074 debug_object_init(&obj, &descr_type_test);
1075 if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1076 goto out;
1077 debug_object_activate(&obj, &descr_type_test);
1078 if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1079 goto out;
1080 __debug_check_no_obj_freed(&obj, sizeof(obj));
1081 if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1082 goto out;
1083 #endif
1084 pr_info("selftest passed\n");
1085
1086 out:
1087 debug_objects_fixups = oldfixups;
1088 debug_objects_warnings = oldwarnings;
1089 descr_test = NULL;
1090
1091 local_irq_restore(flags);
1092 }
1093 #else
1094 static inline void debug_objects_selftest(void) { }
1095 #endif
1096
1097 /*
1098 * Called during early boot to initialize the hash buckets and link
1099 * the static object pool objects into the poll list. After this call
1100 * the object tracker is fully operational.
1101 */
1102 void __init debug_objects_early_init(void)
1103 {
1104 int i;
1105
1106 for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1107 raw_spin_lock_init(&obj_hash[i].lock);
1108
1109 for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1110 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1111 }
1112
1113 /*
1114 * Convert the statically allocated objects to dynamic ones:
1115 */
1116 static int __init debug_objects_replace_static_objects(void)
1117 {
1118 struct debug_bucket *db = obj_hash;
1119 struct hlist_node *tmp;
1120 struct debug_obj *obj, *new;
1121 HLIST_HEAD(objects);
1122 int i, cnt = 0;
1123
1124 for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1125 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1126 if (!obj)
1127 goto free;
1128 kmemleak_ignore(obj);
1129 hlist_add_head(&obj->node, &objects);
1130 }
1131
1132 /*
1133 * When debug_objects_mem_init() is called we know that only
1134 * one CPU is up, so disabling interrupts is enough
1135 * protection. This avoids the lockdep hell of lock ordering.
1136 */
1137 local_irq_disable();
1138
1139 /* Remove the statically allocated objects from the pool */
1140 hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1141 hlist_del(&obj->node);
1142 /* Move the allocated objects to the pool */
1143 hlist_move_list(&objects, &obj_pool);
1144
1145 /* Replace the active object references */
1146 for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1147 hlist_move_list(&db->list, &objects);
1148
1149 hlist_for_each_entry(obj, &objects, node) {
1150 new = hlist_entry(obj_pool.first, typeof(*obj), node);
1151 hlist_del(&new->node);
1152 /* copy object data */
1153 *new = *obj;
1154 hlist_add_head(&new->node, &db->list);
1155 cnt++;
1156 }
1157 }
1158 local_irq_enable();
1159
1160 pr_debug("%d of %d active objects replaced\n",
1161 cnt, obj_pool_used);
1162 return 0;
1163 free:
1164 hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1165 hlist_del(&obj->node);
1166 kmem_cache_free(obj_cache, obj);
1167 }
1168 return -ENOMEM;
1169 }
1170
1171 /*
1172 * Called after the kmem_caches are functional to setup a dedicated
1173 * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1174 * prevents that the debug code is called on kmem_cache_free() for the
1175 * debug tracker objects to avoid recursive calls.
1176 */
1177 void __init debug_objects_mem_init(void)
1178 {
1179 if (!debug_objects_enabled)
1180 return;
1181
1182 obj_cache = kmem_cache_create("debug_objects_cache",
1183 sizeof (struct debug_obj), 0,
1184 SLAB_DEBUG_OBJECTS, NULL);
1185
1186 if (!obj_cache || debug_objects_replace_static_objects()) {
1187 debug_objects_enabled = 0;
1188 if (obj_cache)
1189 kmem_cache_destroy(obj_cache);
1190 pr_warn("out of memory.\n");
1191 } else
1192 debug_objects_selftest();
1193
1194 /*
1195 * Increase the thresholds for allocating and freeing objects
1196 * according to the number of possible CPUs available in the system.
1197 */
1198 debug_objects_pool_size += num_possible_cpus() * 32;
1199 debug_objects_pool_min_level += num_possible_cpus() * 4;
1200 }
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